During a two-hour meeting with the EU's negotiator, Sabine Weyand, the representatives of the Member States insisted that they were not invited to accept the agreement between the two negotiating groups.

They explained to the Commission that they would need the best part of a week to examine the text if the growing nervousness showed itself in front of the prospect of a withdrawal agreement selling a British customs union.

The development makes it less likely to convene a summit on Brexit. EU officials have said privately that November 25 is the last possible date for a summit, and should be convened at the start of next week to facilitate preparations in European capitals. It is expected that the head of Brexit in May, Olly Robbins, will come to Brussels on Sunday because there is no time to reach an agreement.

In order for the EU-27 withdrawal agreement to be agreed, it must include obligations that will never be necessary for a difficult border in Ireland. The EU has suggested that Northern Ireland could remain in the internal market and in the Customs Union. The prime minister said he can not accept such a "shift" in the UK and insists that the whole country remains in a temporary customs union. Brussels sets a high price for this concession, including so-called "level playing field" commitments, to ensure that the British do not have unforeseen competitive advantages.

There is growing frustration with the way the Commission has conducted discussions with the United Kingdom. They conducted them in the "tunnel", a period of private discussion that limited the consultation with the Member States.

The sale of a customs union to the United Kingdom without sufficient commitments, which will subject the United Kingdom to the EU's labor, environmental and social standards and open its seas and fishery resources to European fleets, is particularly concerned.

A senior EU diplomat said: "Member states have insisted that they can not be in the dark, it's just too important."

An elderly diplomat added: "We are very far from a time when we arrive at five o'clock" after the Commission received the information.

"Britain needs to go back to London, get a clear mandate and talk again in Brussels," said an EU diplomat. "There are liquid levels, it's fluid between the Commission and the UK and then flows to London."

The European Commission is expected to expand its non-agreement plans in the coming days against Westminster's increasing volatility. It will also publish laws that will exempt British citizens from their visa requirement as a third country.